S
M
T
W
T
F
S
29
44°
17°
30
61°
30°
31
48°
34°
1
50°
32°
2
45°
30°
3
43°
31°
4
47°
35°
5
44°
37°
6
44°
29°
7
38°
26°
8
42°
33°
9
49°
39°
10
55°
38°
11
54°
43°
12
57°
40°
13
53°
39°
14
54°
36°
15
50°
34°
16
52°
35°
17
51°
33°
18
50°
35°
19
51°
37°
20
48°
38°
21
57°
38°
22
54°
39°
23
49°
39°
24
49°
38°
25
50°
35°
26
48°
33°
27
50°
35°
28
50°
35°
29
51°
36°
30
51°
37°
1
52°
39°
2
52°
37°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
April Weather in Castine
Castine's April 2026 forecast shows daily high temperatures ranging from 38° to 57°, with overnight lows between 26° and 43°. The average high for April is 50° with an average low of 36°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how April weather will actually feel in Castine. See also: May | June | July.
